Brief description of monitoring

Detailed information on monitoring frequency and spatial resolution has not yet been collected from all countries but will be added.

​​Element / parameter

​Nephrops/Population abundance, biomass and distribution

​​Method

​Nephrops are monitored through underwater TV surveys, measuring the landings and discards and this is synthesised together using a stock assessment. Nephrops in the Kattegat is assessed and surveyed jointly with Nephrops in the Skagerrak (what ICES denote as functional units 3 and 4 (FU)). The Danish surveys for blue mussels and oysters occur in Limfjord and the Little Belt. These annual surveys measure abundance, distribution and density of shellfish.

Research vessels are used to carry out the underwater TV surveys for Nephrops. The TV camera is attached to a sledge and the density of the burrows in enumerated. The sampling design is stratified relative to know population variability.

​The Danish surveys for blue mussels and oysters occur in Limfjord and the Little Belt. These annual surveys measure abundance, distribution and density of shellfish. The mussel and oyster surveys are carried out using international norms for bivalve sampling.

​QA/QC

​National

​Frequency

​All surveys, assessment and monitoring are annual.

​Spatial Scope

​For mussels and oysters the scope are the entire Limfjord and Lesser Belt area.

​Spatial resolution

​Mussels – Great Belt (20% as Little Belt only surveyed).

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Monitoring requirements and gaps

Monitoring is to be carried out to fulfill assessment requirements of HELCOM ecological objectives that are specified through HELCOM core indicators. The requirements on monitoring can
include number of stations, the sampling frequency and replication.

​Monitoring requirements

​Monitoring of population state and fishing pressure on bivalves are carried out through local national projects. These are not coordinated Baltic Sea wide. The Nephrops populations and fishery are monitored through an ICES coordinated programme.

​Gaps

There is no central database for shellfish populations in the Baltic Sea. There is no central coordination of monitoring of bivalve populations. Outside Denmark and Sweden, there are no other surveys of shellfish.There is a need for databases and coordination under D3.

Adequacy for assessment of GES (Q5d)

Monitoring should provide adequate data and information to enable the periodic assessment of environmental status, and distance from and progress towards GES as required by MSFD under Article 9 and 11.

​Adequate data?​

​No

​Established methods for assessment?

​No

​Adequate understanding of GES?

​No

​Adequate capacity to perform assessments?

​​No

Assessment of natural variability (Q5e)

If shellfish need to be considered within the Baltic Sea area, there is little coordinated monitoring on any species other than Nephrops.